Machine for molding plastic materials.



No. 692,778.- Patenteidfeb. 4, 19022'-y w-. BommwE & J. LUMLEY.

. MACHINE FOR MLDING PLASTIC MATERIALS.

f (Application tiled hule4 1, 1900. Ronewed July 24, 1901.) (No Model.)v

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Tn: Nonms sirens co, PHoYaLrmo., m/ Asnxnomm u. c.

UNITED STATES PATENT OEEICE.A

WILLIAM BORROWE AND JOHN LUMLEY, OF SAN FRANCISCO, CALIFORNIA;

SAID BORROWE ASSIGNOR TO MARY ELIZABETH BORROVE, OF SAU- SALITO,CALIFORNIA.

MACHINE FOR MOLDING PLASTIC MATERIALS.

SPECIFICATION forming part of Letters Patent No. 692,778, dated February4, 1902.

Application filed June 1I 1900. Renewed J'uly 24, 1901. Serial No.69,581. (No model.)

To all whom it may concern:

Be it known that we, WILLIAM BORROWE and JOHN LUINILEY, citizens of theUnited States of America, residing at San Francisco,

county of San Francisco, and State of California,have invented certainnew and useful Improvements in Machines for Molding Plastic Materials;and we hereby declare the following to be a full, clear, and exactdescripr'o tion of the same, reference being had to the accompanyingdrawings,t`orminga part of this specification.

Our invention relates to a machine for molding and shaping cylinders,slabs, and other t5 forms of heat-insulating material when such materialis in a plastic state, and is animprovement on machinery and apparatusset forth in Letters Patent No. 629,102, relating to machinery forpreparing pipe-covering, 2e granted to us on the`18th day of July, 1899.

Our present improvement consists in combining with means for molding,shaping, and smoothing the plastic articles means for automaticallyfeeding the prepared 'plastic in- 2 5 sulatingA material to the moldingmechanism in such graduated and regulable quantity and in such manner asthat the said material shall not suer injurious compression whereby itsheat-insulating properties may be impaired 3o in the treatment.

The objects of our invention are yto obtain a regular and completeperformance of the machinery, a more perfect product, and increasedcelerity of the Work in shaping or 3 5 molding both at and circularforms.

Referring to the drawings, Figure I is a side elevation of a machine fornioldin g either flat or curved forms of plastic material constructedaccording to ourinvention. Fig. Il

4o is a plan View of the lsame machine. Fig. III isan end view, partlyin section, when the machine is arranged for forms of a curved section.Fig. IV is an end view,partly in section, when the machine is arrangedto produce forms of a tlat or rectangular section.

Fig. Vis a sectional view of one'of the smoothing-dies to iinish andsmooth the surfaces of the sections.

In the preparation of material for heat insulation the processes,Whatever their nature, should be such as to not compact the plasticmaterial in such manner or degree as. to destroy its porosity, becausethe efficiency or insulating value of such material depends in greatdegree on its cellular structure andthe xed air contained therein. Thisrequirement prohibits the extrusion and other processes, such as aresuitable for molding plasterial, preferably ot' cellular structure, to

form a mechanical bond, the compound being mixed with water or otherliquid to a plastic condition, after which the material 'is molded intovarious sections, such as are required in use to` coverwalls, pipes, orvessels for the purpose of either repelling or retaining heat, as may berequired.

To these ends We construct machinery subf stantially as shown in thedrawings, consisting of a main supportingframe 1, provided withshaping-rollers 2, having a contour to fit the desired form of thesections' 3 of insulating material, curved, as in Fig. III, to form ahalf tube or cylinder, such as is employed in covering pipes, or in iiatsection, as in Fig. IV, to cover plain surfaces, also any other form ofuniform section that may be required. These sections 3 are molded orshaped on bottom boards or forms/.t to give the required shape on oneside, corresponding to that of the rollers 2, and to support thematerial while it dicated by arrows in Fig. I.

is soft and in a plastic condition and While being dried, after which itbecomes rigid and is removed from the forms 4 for trimming andsubsequent treatment, such as covering with cloth. The forms 4 are movedpositively through the machine by means of a conveyer or endless band 5,provided with spaced stopsV 7, against which the forms a abut, as shownin Fig. I, forming a nearly-continuous line or row, with short spaces Sbetween. rlhe conVeyer-band 5 passes around drums 9 and 10, one at eachend, suitably supported on the shafts 12 and 13, the latter beingdriven, preferably, by a band on the pulley 14, connectin g with aline-shaft or the driving power. The rollers 2 are driven by means of acontinuous band or belt 15, passing around the pulleys 17 and 18, overand under idle pulleys 19 and 20, and around the pulley 22 at the end,as shown in Fig. I, the latter-named pulley driving the devices tosupply the material, as hereinafter explained. The size of the pulleys17 and 18 and the speed of the band 15 are so arranged that theperipheries of the shaping-rollers 2 move faster relatively than theconveyer-band 5, thus producing a rubbing action that smooths thesurface of the material and prevents it from adhering to the rollerswhen of a viscous nature. It may seem that the limited area of contacton the pulleys 17 and 18 is notenough to impel the rollers 2; but itmust be remembered that the material throughout has to be treated in agentle manner in so far as pressure to avoid compactment of theparticles and closure of the cells or interstices on Which theefficiency of the finished material depends. After passing beneath theforming-rollers 2, Which, as before explained, can be of any desiredligure or contour, the sections or pieces 3 pass through thesmoothing-dies 23 24. (Shown in Fig. I.) These dies are made of smoothnoncorrosve metal and are attached to the main frame 1 by the clamps 25.These dies 23 24 are slightly tapered, as shown, and diminish in size inthe direction of movement, as in- In this manner of operating it Will beobvious that the plastic material has to be supplied in definitequantity or in proportion to the movement of the conveyer-band 5, andthis constitutes a chief difficulty in the operation, because thedevices for regulation must not condense, but rarefy the material andpermit as far as possible the incorporation of air in the mass at thepoint of its entering beneath the rollers 2. For this purpose We employa revolving helical conveyer 27, placed in the bottom of thesupply-hopper 28 and adjustable in respect to its axis of revolution tovarious angles, so that it advances a variable amount of material to andbeneath the rollers 2, dependent on adjustment. The helix or screw 27 issupported lin a bearing member 20, adjustably clamped to the sides ofthe main frame 1 by the screws 30 and is driven by bevel-Wheels 32 fromthe shaft 33, as shown in Figs. III and IV. Curved slots 34., formed inthe sides of the main frame, permit adjustment of the screw 27concentrically about the axis of the shaft 33, so the gear-Wheels 32will be held in true engagement. By raising or lowering the outer end ofthe screw 27 so the material advanced will impinge upon or pass beneaththe rst roller 2 the pressure there, the amount of compression, and thequantity of the material passing can-be successfully adjusted. The screw27 besides this function mixes and incorporates the plastic substancebefore it is molded. The material previous to passing to the hopper 28is saturated and passes through any suitable mixing apparatus, such asis employed for like purposes.

It will be understood that the number of shaping-rollers and the numberof the smoothing-dies 24C can be more or less as the nature of thematerial may require. Pairs of each are found to be sufficient inmolding material consisting of diatomaceous earth and the usual fibrouscomponent.

IIaving thus described the nature and objects of our invention andpractical means of its application, what We claim as new, and desire tosecure by Letters Patent, is-- 1. In a molding-machine for porousplastics, a series of forms for supporting the plastic material, meansfor advancing said forms in succession, a hopper above said line offorms, molding andsmoothing rollers above said forms for shaping andfinishing the upper su rface of the plastic material, and regulablemeans in connection with said hopper for feeding the plastic material tothe forms and rollers in graduated quantity without compression,substantially as specified.

2. In a molding-machine for porous plastics, a series of forms forsupporting the plastic material, a conveyor for carrying forward saidforms in a straight line, molding and smoothing rollers above saidconveyer, With means for driving the same at a surface speed slightly inexcess of that of the conveyer, and in combination therewith means forfeeding the plastic material to said forms in graduated and regulablequantity without compression, substantially as specified.

3. In a molding-machine for porous plastics, a series of forms forsupporting the plastic material, a conveyer for carrying forward saidforms in a straight line, rollers above said conveyer for giving shapeand smoothness to the said material passing beneath them, means fordriving said rollers at a surface speed slightly greater than that ofthe forms, means for feeding the plastic material to the forms ingraduated and regulable quantity without compression, and smoothingdiesto complete the shape and finish of the plastic articles carried beneaththem, substantially as specified.

4. In a molding-machine vfor plastic Inate- In testimony whereof We havesigned our rc3v rial, a continuously-moving eonve'yer-band names to thisspecification in the presence of 5, a seriel of bottomforms 4thereon andadtwo subscribing Witnesses. Vauced t ere y, superimposed rollers tomold Y 5 and shape the material on the forms, these latter driven byaband 15 at a rate in excess 0f the movement of the material to produceWitnesses: a rubbing action thereon, substantially as ALFRED A. ENQUIST,speeiied. l ELMER WICKEs.

